Addition Effects Research Articles

Potentiation of Antibacterial Activity of Ciprofloxacin by Essential Oil of Cymbopogon citratus against Fluoroquinolone-resistant Staphylococcus aureus and Escherichia coli

Background: Essential oil (EO) of Cymbopogon citratus has been demonstrated to have antibacterial activities against both Gram negative and Gram positive bacteria. The study was, therefore, conducted to evaluate the effects of combined use of C. citratus and ciprofloxacin against fluoroquinolone-resistant Staphylococcus aureus (FQRSA) and Escherichia coli (FQREC).
 Methods: The antibacterial activity of the essential oil was evaluated by agar dilution method while the combination studies were done using Checker-board agar dilution technique.
 Results: The mean MIC values of EO against the FQRSA and FQREC were 0.043 + 0.01 mg/ml and 0.049 mg/ml respectively. When ciprofloxacin was combined with EO of lemongrass, 53.9, 28.3, 17.8 and 0.0 % of the FQRSA isolates showed indifference, additive, synergistic and antagonistic effects respectively. Similarly, when ciprofloxacin was combined with EO of lemongrass at different ratios, 44, 35.5, 20.6 and 0.0 % of the FQREC isolates showed combined effects of additivity, synergism, indifference and antagonism respectively.
 Conclusions: The results revealed the invitro antibacterial potency of Cymbopogon citratus oil against fluoroquinolone resistant S. aureus and E. coli. More importantly, the study has proved that the combined use of ciprofloxacin and essential oil of lemongrass has increased the sensitivity of both FQRSA and FQREC bacteria.

Effects of B2O3-Bi2O3 addition on the dielectric properties of low-temperature-sintered MgO-TiO2(w) ceramics

The effects of different contents of B2O3-Bi2O3 on the sintering temperature and dielectric properties of MgO-12%TiO2(w) ceramics were investigated. B2O3-Bi2O3 addition effectively reduced the sintering temperature and improved the dielectric properties of ceramic samples; however, an excessive amount of B2O3-Bi2O3 led to the deterioration of dielectric properties. This is because Bi2O3 participated in the chemical reaction between MgO and TiO2 and generated a high-dielectric-loss Bi2Ti2O7 phase, resulting in an increased dielectric loss in the ceramic samples. In contrast, B2O3 formed a liquid phase to fill the grain gaps and pores during sintering, improving the densities of the ceramic samples. An appropriate amount of B2O3-Bi2O3 accelerated the reaction between MgO and TiO2 and formed ultralow-dielectric-loss phases—MgTiO3 and Mg2TiO4, and the dielectric losses of the ceramic samples decreased to an order of 10−5.

Conductive Additives Effects on NCA–LFMP Composite Cathode in Water-Based Binder for High-Safety Lithium-Ion Batteries

Lithium nickel–cobalt–aluminum oxide (NCA) is a promising cathode material for lithium-ion batteries due to its high energy density of more than 274 mAh/g. However, thermal runaway inhibits its practical applications. Lithium ferromanganese phosphate (LFMP), due to its olivine structure, can effectively stabilize the surface stability of NCA and reduce the exothermic reactions that occur during thermal runaway. LFMP can also inhibit cathode expansion and contraction during charging and discharging. To improve the conductivity of an NCM–LFMP composite electrode, three different conductive additives, namely carbon black, carbon nanotubes (CNTs), and graphene, were introduced into the electrode. Finally, battery safety tests were conducted on 1.1 Ah pouch cells fabricated in the present study. The energy density of the NCA–LFMP 1.1 Ah lithium-ion pouch cells with only 0.16% CNT content reached 224.8 Wh/kg. The CNT–NCA–LFMP pouch cell was also the safest among the cells tested. These results provide a strategy for designing high-energy-density and safe pouch cells for energy storage device applications.

Fe and Zn Addition Effects of Ti Oxide-Based Electrocatalyst on Catalytic Activity for Oxygen Reduction Reaction

The conventional catalyst of polymer electrolyte fuel cell (PEFC) is a platinum which is categorized as precious metal with very high-cost material, and its performance is limited in principal. From this point of view, the non-precious metal electrocatalyst should be required. We have focused and studied group 4 and 5 metal oxide-based electrocatalyst as non-platinum catalysts for the oxygen reduction reaction (ORR) because of low-cost, abundant reserves, and high stability in acidic electrolytes [1-2]. We found that titanium oxide prepared from TiOTPyzPz supported on multi-walled carbon nanotubes had superior ORR activity [3]. On the other hand, it was published as an international patent that the addition of other elements such as Fe and Ni is affected to enhance the ORR activity of Ti oxide-based electrocatalyst [4]. We have also applied for the TiOTPyzPz as a starting material with Fe, Ni, and Zn addition to enhance the ORR activity of Ti oxide-based electrocatalyst [5-6]. In this study, we have investigated the addition effects of Zn and Fe for Ti oxide-based electrocatalyst on the catalytic activity for the ORR.2,3-Dicyanopyrazine, urea, and Ti isopropoxide were dissolved in quinoline and refluxed to synthesize TiOTPyzPz. Iron acetate and zinc acetate were also added to dissolve in quinoline to obtain the Fe and Zn-added TiOTPyzPz as a starting material. These starting materials were mixed with carbon nanotube by ball-milling to prepare the precursors. These precursors were heat-treated under low oxygen partial pressure at 900 oC for 3 h to obtain the oxide-based electrocatalyst powder. The catalyst powder was dispersed into 1-propanol with Nafion solution to prepare a catalyst ink. The ink was dropped on a glassy carbon rod to use as a working electrode in electrochemical measurement.Electrochemical measurements were performed in 0.5 mol dm-3 H2SO4 at 30 oC with a conventional 3-electrode cell. A reversible hydrogen electrode (RHE) and a glassy carbon plate were used as used as a reference and counter electrode, respectively. Slow scan voltammetry (SSV) was performed at a scan rate of 5 mV s-1 from 0.2 V to 1.2 V vs. RHE under O2 and N2. The ORR current (i ORR) was determined by calculating the difference between the current under O2 and N2.Figure 1 shows the ORR polarization curves Fe and/or Zn addition to the Ti oxide-based electrocatalysts. The Fe and Zn added Ti oxide-based electrocatalyst (Fe,Zn-TiOx) was obviously the highest activity for the ORR, and it was higher ORR activity than Fe added Ti oxide-based electrocatalyst (Fe-TiOx), Zn added Ti oxide-based electrocatalyst (Zn-TiOx), and Ti oxide-based electrocatalyst (TiOx) without addition. It reveals that the addition of Fe and Zn was found to be effective for enhancing the ORR activity, and Fe addition was more effective than Zn addition for enhancing the ORR activity. XRD pattern of TiOx shows several peaks identified TiO2-Rutile and TiC0.3N0.7 while the XRD pattern of Fe-TiOx, Zn-TiOx, and Fe,Zn-TiOx also shows several peaks identified similar to TiOx. According to results from ICP analysis, the contain amount of Ti and Fe in Fe,Zn-TiOx was similar to preparation amount in precursor, but that of Zn showed below detection limit. From SEM images, Zn-TiOx and Fe,Zn-TiOx have more space in its powder than Fe-TiOx and TiOx. Based on above results, it is suggested that Zn addition affected to increased electrochemical surface area of TiOx, and Fe addition affected to form active site [7] in TiOx as similar case as Zr oxide-based electrocatalyst [8].Acknowledgement: The authors thank New Energy and Industrial Technology Development Organization (NEDO) and ENEOS Tonen General Research / Development Encouragement & Scholarship Foundation for financial support.Reference A. Ishihara, Y. Ohgi, K. Matsuzawa, S. Mitsushima, and K. Ota, Electrochim. Acta, 55, 8005 (2010).A. Ishihara, S. Tominaka, S. Mitsushima, H. Imai, H. Imai, O. Sugino, and K. Ota, Curr. Opin. Electrochem., 21 , 234 (2020).S. Tominaka, A. Ishihara, T. Nagai, and K. Ota, ACS Omega, 2, 5209 (2017).K. Takahashi, T. Imai, R. Monden, Y. Wakisaka, and S. Sato, Oxygen Reduction Catalyst, Process for Producing Same, and Polymer Electrolyte Membrane Fuel Cell, WO/2013/008501.K. Matsuzawa, M. Obata, Y. Takeuchi, Y. Ohgi, K. Ikegami, T. Nagai, R. Monden and A. Ishihara, ECS Trans., 108(7), 181 (2022).K. Matsuzawa, M. Obata, Y. Takeuchi, Y. Ohgi, K. Ikegami, T. Nagai, R. Monden and A. Ishihara, ECS Trans., 108(7), 189 (2022).J-H. Kim, A. Ishihara, S. Mitsushima, N. Kamiya, and K. Ota, Acta, 52, 2492 (2007).Y. Takeuchi, K. Watanabe, K. Matsuzawa, T. Nagai, K. Ikegami, R. Monden, and A. Ishihara, Chem. Lett., 51, 927 (2022). Figure 1

Effectiveness of flue gas desulfurization gypsum in reducing phosphorus solubility in poultry litter when applied as an in-house amendment

Phosphorus (P) runoff from agricultural lands receiving poultry litter (PL) poses a major environmental challenge. Application of flue-gas-desulfurization (FGD)-gypsum produced from coal power plants in agricultural lands has shown promise to reduce P losses. However, no information is available about the effectiveness of FGD-gypsum addition in reducing P solubility when applied as an in-house amendment. Hence, the objectives of this study were to understand a) effectiveness of FGD-gypsum as a litter amendment in reducing P loss risk; and b) how FGD-gypsum amendment in PL alters the distribution of P forms. Broiler chickens were raised for five flocks in seven individual litter treatments replicated four times in a randomized complete block design. Based on the FGD-gypsum addition, the PL treatments were broadly classified as FGD-gypsum treated and untreated. Toxic metal concentrations were analyzed in FGD-gypsum as well as the treatments. Sequential water extractions were performed to understand P solubility. Litter P fractionation was performed to identify bioavailable P (Water-P), labile P (NaHCO3-P), aluminum/iron chemisorbed P (NaOH-P), and mineral occluded P (HCl-P). Results indicated significantly higher soluble P in all untreated than in all FGD-gypsum treated litters in the initial water extraction. The FGD-gypsum treated litters reduced soluble P by 58 to 67% in the 1st water extraction compared to untreated litters. Fractionation study revealed lower proportion of Water-P and higher proportion of NaHCO3-P and HCl-P in all FGD-gypsum treated than in untreated litters. This study suggests reuse of FGD-gypsum in broiler houses can help reduce P mobility without any toxic metals concerns.

Highly effective adsorption and passivation of Cd from wastewater and soil by MgO- and Fe3O4-loaded biochar nanocomposites

Introduction: The application of Fe- (BC-Fe) and Mg-modified (BC-Mg) biochars for the remediation of heavy-metal-contaminated soil has become a research hotspot in recent years. It is critical to select suitable biochar for soil rejuvenation under the same pollution condition.Methods: In this study, the biochars were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). In addition, the adsorption and passivation effects of BC-Fe and BC-Mg were comprehensively evaluated through batch adsorption experiments and soil incubation experiments, and the effects of Cd-contaminated soil on plant growth were also demonstrated by pot experiments.Results: SEM, FTIR, and XRD showed that MgO and Fe3O4 nanoparticles were successfully loaded on the biochar surface. The maximum adsorption efficiencies of BC-Fe and BC-Mg for Cd were 52.63 and 66.23 mg g−1, which was 9.05 and 7.19 times higher than that of the original biochar (7.32 mg g−1), respectively. Soil culture experiment showed that 5% BC-Fe and BC-Mg significantly reduced soil DTPA-Cd content by 38.86% and 50.85% at 120 days, respectively. In addition, BC-Fe and BC-Mg promoted the conversion of acid-soluble Cd to the oxidizable and residual states. Pot experiments revealed that BC-Fe and BC-Mg reduced the Cd content in shoots of the maize by 3.97 and 6.09 times, respectively, and both significantly increased the dry and fresh weights of the shoots and roots of the maize plants. Moreover, BC, BC-Fe, and BC-Mg provided nutrients required for plant growth to the soil and increased the activities of soil dehydrogenase, urease, and peroxidase. The adsorption–passivation mechanism of BC-Fe on Cd mainly included electrostatic attraction, while the adsorption–passivation mechanism of BC-Mg on Cd included precipitation and ion exchange.Discussion: Overall, the results showed that BC-Mg can be used as an efficient functional material for heavy-metal pollution remediation, and this study provided guidance on the selection of passivator materials for heavy-metal-contaminated soil remediation.

Effects of foods and food components on the in vitro bioaccessibility of total arsenic and arsenic species from Hizikia fusiforme seaweed

Seaweed is an important food source, especially in many Asian countries, because of its high nutritional value; however, increasing arsenic (As) accumulation may pose serious hazards to human health. The influence of food components on As bioaccessibility and transformation in the high As-containing seaweed Hizikia fusiforme was determined using an in vitro gastrointestinal digestion method. The results showed that co-digestion with several daily foods (such as celery, broccoli, onion, green chili, tomato) produced a higher As bioaccessibility (approximately 6–11 % increase) compared with that of seaweed alone. Vegetables such as fennel (Foeniculum valgare Mill.), celery (Apium grareolens L.), blanched garlic leaves (Allium sativum L.), scallions (Allium fistulosum L.), ginger (Zingiber officinale Rosc.), and green pepper (Capsicum frutescens L. vat. grussum Bailey) decreased bioaccessible inorganic As (18–35 %) in both the gastric and small intestinal phases. Meanwhile, the process of reducing As(V) to As(III) also occurred during co-digestion with some food matrices. Egg white and other animal proteins were the most effective reducing agents, transforming >70 % As(V) into As(III) in the solution system. These results may have important implications for health risk assessment via co-consumption. The present study provides the first evidence showing that the co-consumption of some vegetables and proteins leads to a higher toxicity of inorganic arsenic-containing food. In addition, the positive and negative effects of co-digestion on the bioaccessibility of essential metals (iron, manganese) compared to single digestion were evaluated in this study.

Oleuropein as An Effective Suppressor of Inflammation and MicroRNA-146a Expression in Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a common progressive autoimmune disorder that causes chronic inflammation of the joints and damage to other organs. Previous studies have reported the important role of miRNA-146a in the pathogenesis of RA. In addition, the anti-inflammatory and modulatory effects of oleuropein (OLEU) on the expression pattern of microRNAs (miRNAs) have been shown in different diseases. Therefore, this study aimed to evaluate both the sensitivity and specificity of miRNA-146a and determine the potential effects of OLEU on the expression levels of miRNA-146a and tumour necrosis factor-alpha (TNF-α) in RA patients. The participants in this experimental study were divided into 2 groups: RA (n=45) and healthy controls (n=30). The isolated peripheral blood mononuclear cells (PBMCs) were treated with different concentrations of OLEU; and the level of TNF-α expression, anti-citrullinated protein, and miRNA-146a were determined using enzyme-linked immunoassay and real-time polymerase chain reaction, respectively. In addition, the receiver operating characteristic (ROC) curve analysis evaluated the sensitivity and specificity of miRNA-146a in RA patients. Results revealed a positive correlation between the levels of miRNA-146a expression with the serum levels of C-reactive protein (CRP) and rheumatoid factor (RF) in RA patients. In addition, OLEU treatment decreased the levels of TNF-α and miRNA-146a expression in treated PBMCs samples compared with untreated cells. The ROC curve analysis showed an 85% sensitivity and 100% specificity of miRNA-146a in RA patients. Therefore, miRNA-146a can be used as a useful biomarker for RA diagnosis, particularly for early detection. In addition, OLEU could suppress inflammation in RA patients through the regulation of miRNA-146a.

Microbial food web changes induced by terrestrial organic matter and elevated temperature in the coastal northern Baltic Sea

Climate change has been projected to cause increased temperature and amplified inflows of terrestrial organic matter to coastal areas in northern Europe. Consequently, changes at the base of the food web favoring heterotrophic bacteria over phytoplankton are expected, affecting the food web structure. We tested this hypothesis using an outdoor shallow mesocosm system in the northern Baltic Sea in early summer, where the effects of increased temperature (+ 3°C) and terrestrial matter inputs were studied following the system dynamics and conducting grazing experiments. Juvenile perch constituted the highest trophic level in the system, which exerted strong predation on the zooplankton community. Perch subsequently released the microbial food web from heavy grazing by mesozooplankton. Addition of terrestrial matter had a stronger effect on the microbial food web than the temperature increase, because terrestrial organic matter and accompanying nutrients promoted both heterotrophic bacterial production and phytoplankton primary production. Moreover, due to the shallow water column in the experiment, terrestrial matter addition did not reduce the light below the photosynthesis saturation level, and in these conditions, the net-autotrophy was strengthened by terrestrial matter enrichment. In combination with elevated temperature, the terrestrial matter addition effects were intensified, further shifting the size distribution of the microbial food web base from picoplankton to microphytoplankton. These changes up the food web led to increase in the biomass and proportion of large-sized ciliates (>60 µm) and rotifers. Despite the shifts in the microbial food web size structure, grazing experiments suggested that the pathway from picoplankton to nano- and microzooplankton constituted the major energy flow in all treatments. The study implies that the microbial food web compartments in shallow coastal waters will adjust to climate induced increased inputs of terrestrial matter and elevated temperature, and that the major energy path will flow from picoplankton to large-sized ciliates during the summer period.

Intended and unintended impacts of nitrogen-fixing microorganisms and microbial inhibitors on nitrogen losses in contrasting maize cropping systems.

Efforts to mitigate the nitrogen (N) footprint of maize production include using N-fixing microbes (NFM) and/or microbial inhibitors. We quantified the effects of NFM, the nitrification inhibitor (NI) DMPSA, and the urease inhibitor (UI) NBPT, each applied by itself or paired with another additive, on nitrous oxide (N2 O) emissions, nitrate (NO3 - ) leaching, and crop performance in contrasting irrigated and rainfed maize systems over two growing seasons. We also used published emission factors to estimate indirect N2 O emissions from leached NO3 - that can be converted to N2 O. Agronomic effects were relatively small; the NI+NFM treatment increased N use efficiency and grain yield and protein content in some cases by 11-14% relative to a treatment receiving only urea. Most of the additive treatments reduced direct (in-field) N2 O emissions, most consistently for treatments that contained NI which reduced emissions by 24-77%. However, these beneficial effects were counteracted by increased NO3 - leaching, which occurred most consistently with UI or NFM applied as single additives or with NI. In these treatments, NO3 - leaching increased during at least one growing season, and at both sites, by factors of 2 to 7. In three site-years, increased NO3 - leaching with NFM and NI+NFM offset large reductions in direct N2 O, such that total direct + indirect N2 O emissions were not different from that in the urea-only treatment. These unintended effects may have resulted from unfavorable rainfall timing, varying crop N demand, and declining additive effectiveness. Use of these soil additives requires caution and further study. This article is protected by copyright. All rights reserved.

CEO power, audit committee effectiveness and earnings quality

PurposeThe purpose of this study is to establish the relationship between chief executive officer (CEO) power, audit committee effectiveness and earnings quality in regulated firms in Uganda.Design/methodology/approachThe authors employed cross-sectional and correlational research designs, based on a sample of 136 regulated firms in Uganda. Data were collected using a questionnaire survey from Chief Finance Officers and Chief Audit Executives. Data were analyzed using a Statistical Package for Social Sciences and Partial Least Squares Structural Equation Modeling.FindingsResults indicate that CEO power causes negative variances in earnings quality. The results also reveal that audit committee effectiveness positively relates relatively similarly with earnings quality. In addition, CEO power and audit committee effectiveness are negative and significantly related. The results further indicate that CEO power and earnings quality are mediated by audit committee effectiveness.Research limitations/implicationsCEO power creates an opaque accounting environment which may leave the stakeholders unable to evaluate the true economic reality of the firm. Audit committee effectiveness is an important enabler for reporting high-quality earnings even in the presence of a powerful CEO.Originality/valueThis study contributes toward a methodological stance of using perceptions to understand earnings quality in regulated firms in Uganda. This is probably the first study that has specifically explored earnings quality using only the fundamental qualitative characteristics of accounting information (as proxies) as enshrined in the Conceptual Framework for Financial Reporting 2018 particularly in Uganda since Her adoption of International Financial Reporting Standards in 1998. Second, the indirect effect of audit committee effectiveness and CEO power is tested.

Increased oxygen vacancies and Sc doping in ZnO promote bacterial disinfection and methyl orange degradation

Semiconductor materials exhibit poor absorption of visible light as well as high charge recombination rates, which considerably limit their photoconversion efficiency. In this study, a higher photoconversion versatile photocatalyst, namely ZnO@SiO2 was doped with Sc and was synthesized to degrade methyl orange and inactivate bacteria efficiently. Although the undoped materials were oxygen vacant, they failed to efficiently degrade organic pollutants. What our research demonstrates is the effectiveness of Sc addition to making such ZnO material for the degradation of methyl orange and inactivation of bacteria. In addition, we have studied in detail the process of superoxide anions damage to methyl orange and Escherichia coli during degradation, and this study will guide the expansion of applications in photocatalysis by doping with rare earth elements. Meanwhile, this material with no color has potentially valuable applications in water purification.

Behaviour of autoclaved magnesium oxysulfate cement pastes

This study investigates the influence of autoclave curing on Magnesium Oxysulfate Cement cement compared to acid addition effects, especially on microstructure and mechanical properties. For this purpose, compressive and flexural strength, water resistance and volume stability were analysed. In addition, X-ray diffraction and Scanning Electron Microscopy were applied to verify the phase composition and microstructure of these matrices. Results indicate that the autoclave process affects the mechanical properties. The increase in the molar ratio reduces flexural strength and slightly increases the compressive strength. The autoclave also reduces water resistance, especially with increasing curing time. Longer autoclaving time (4 h) increases expansion in the pastes, which stabilize in around 30 days. In the microstructure, autoclaving reduces or inhibits the formation of the 517 phase, which is responsible for increased mechanical strength, and provides the formation of the Mg(OH)2 and 512 or 513 phase. Thus, in MOS cement, the autoclave process mainly promotes the formation of 512 or 513 phases. Therefore, the material can be improved to be submitted to curing in an autoclave and present an increase in mechanical properties, which will provide the large-scale production of lightweight boards in the construction materials industry and may influence the increase in the use of this material in construction.

Modified Darcy’s law and couple stress effects on electro-osmotic flow of non-Newtonian nanofluid with peristalsis

In this study, we focused on the heat transfer through a uniformly inclined rectangular duct caused by the electro-osmotic peristaltic flow of an unsteady non-Newtonian nanofluid. With couple stress, the fluid obeys the Papanastasiou model. The flow is through a porous medium that follows Darcy’s law in a modified form. In addition, Dufour and Soret effects, mixed convection, the impacts of a chemical reaction, and the effects of viscous couple stress dissipation are all considered. The governing equations that explain the velocity, temperature, and concentration of nanoparticles are simplified when wave transformation is used. The homotopy perturbation method was used to solve these equations analytically. Additionally, a collection of figures is used to discuss and visually illustrate the consequences of the physical characteristics. In fact, the modified Darcy’s law makes the velocity gradient appear in the momentum equation, which increases the contribution of the velocity gradient to the velocity profile. In addition, the electro-osmotic parameter and Helmholtz-Smoluchowski velocity have a significant impact on the velocity gradient’s direction, as well as the velocity gradient’s ability to be either positive or negative, depending on their values. In addition, in the case of forced convection, the values of the Nusselt number and the Sherwood number are highly affected by the value of Helmholtz–Smoluchowski velocity. The current findings have applications in biology and medicine, particularly in cancer therapy, which involves peristaltic blood pumps(arteries) and suspended gold nanoparticles (nanofluid). According to our knowledge, no prior studies have merged the couple stress Papanastasiou model and the modified Darcy’s law.

How Does FDI Enhance Urban Sustainable Competitiveness in China?

Urban sustainable competitiveness (USC) is one of the important indexes to measure the high-quality development of cities in China. Meanwhile, foreign direct investment (FDI) plays the prominent role in improving urban sustainable competitiveness. Therefore, this analysis aimed to test the impact of FDI on the USC and its mechanism using the intermediary effect model with a sample of 282 cities in China during the period 2012–2018. The influencing mechanism includes the scale effect, the technological effect, and the structural effects. The results show that: first, FDI is significantly and positively related to the USC of China, and the scale, technological and structure effects all play a mediating role, with the scale effects being the most significant. Moreover, population size shows negative effect on the USC. Second, the impact of FDI on the USC is regionally heterogeneous. FDI can significantly improve the USC in the eastern region, but has no significant effects on the northeastern, central and western regions. Third, FDI in the eastern region affects USC through structural effects, while the scale and technological effects do not play a mediating role but both effects can directly affect USC. FDI in the northeast region still has the structural effect, but this structural effect does not indirectly affect USC, while FDI in the western region has both scale and structural effects. In addition, the technological and structural effects in the central region have a direct impact on USC, while the scale effect in the western region has a direct impact on USC. Therefore, the findings suggest that utilizing FDI should take into account regional characteristics in China.

Co-Gasification Performance of Low-Quality Lignite with Woody Wastes Using Greenhouse Gas CO2—A TG–MS Study

The carbon dioxide gasification performance of low-quality lignite-agroindustrial/forest waste blends was investigated in terms of reactivity, conversion, cold gas efficiency, product gas composition and heating value. The experiments were conducted in a fixed bed unit and a thermal analysis mass spectrometer system. Raw materials, chars, liquids and gases were quantitatively analyzed and their energy content was determined. Synergetic effects and the role of minerals were examined, the latter through chemical and fusibility analyses of the ashes. Ahlada lignite (AL) was of low quality, with a calorific value of 8.9 MJ/kg. The biomass materials, ginning cotton waste (GCW) and pine needles (PN) had calorific values 16.6 MJ/kg and 20.1 MJ/kg, respectively. The slagging/fouling propensity of AL ash was low, whereas that of biomass wastes was medium to high. Thermal treatment of the samples and their blends prior to gasification produced upgraded fuels. A Boudourd reaction occurred above 750 °C. Gasification reactivity followed the order: GCW > PN > AL. AL/PN mixtures presented additivity effects; however, AL/GCW mixtures presented synergy effects. When the lignite was blended with the biochars studied, its conversion increased from 90% to 94.5% and its cold gas efficiency from 31.8% to 35%. Generated gas attained a heating value of about 12 MJ/m3.

Enhanced drug carrier capacity after post modification process for amino acid substitute phosphazene based microspheres with anticancer activity

In this study, drug carrier HCCP-PP-LEEMP microspheres were synthesized by using Hexachlorocyclotriphosphazene (HCCP), Phenolphthalein (PP) and l-Lysine Ethyl Ester Dihydrochloride (LEE) by polycondensation reaction. The synthesized spheres were modified in an acidic environment, and a cationic charge was formed on their surfaces. Synthesized and quaternized microspheres were characterized using FT-IR, SEM, TEM, TGA and Zeta (ζ) potentials analyzes. HCCP-PP-LEE-ATA-QMP microspheres with increased anionic drug carrying capacity as a result of quaternization were used as carriers for Sodium Diclofenac (NaDc) and Cimetidine drugs. While the unmodified HCCP-PP-LEEMP microspheres did not retain the NaDc drug, the NaDc drug retention capacity of the quaternized HCCP-PP-LEE-ATA-QMP microspheres was calculated as 99.6677 mg/g. Thus, it was determined that the drug holding capacity of the microspheres could be increased tens of times compared to their initial state, thanks to the positive charges formed on the surface of the drug carrier microspheres as a result of quaternization. At the same time, Cimetidine, a type of chemotherapeutic drug, was loaded into the microsphere using as drug delivery system. In vitro drug release behaviors of the developed phosphazene and amino acid-based delivery system were investigated and drug release kinetic models were determined. In addition, the antibacterial and antifungal effects of the microspheres were investigated with the effect of LEE in the structure of the microspheres. Then, the anticancer behavior of the cimetidine-loaded microspheres was tested on HT-29 colon cancer cell lines. Thus, a potential carrier system that can carry drugs for the treatment of a selective disease or chemotherapeutics for the treatment of cancer has been synthesized.

P35 Heteroresistance to cefiderocol in clinical Gram-negative isolates

Abstract Background Heteroresistance is a phenotype in which a clinically susceptible bacterial isolate contains less susceptible subpopulations. Unexpectedly high levels of treatment failure for cefiderocol, a novel antibiotic designed to treat multidrug-resistant infections, have been attributed to this phenomenon. Objectives To determine prevalence of cefiderocol heteroresistance amongst clinical isolates at a North London tertiary care centre and study the population dynamics upon exposure to the antibiotic. Methods Gram-negative clinical isolates (n = 146) were screened for cefiderocol susceptibility by standard disc diffusion and Etest assays. Isolates were classified based on EUCAST breakpoints for cefiderocol susceptibility. Heteroresistance was confirmed by performing modified-population analysis profile (mPAP) assay in iron-depleted Mueller Hinton II agar. MIC values were determined by broth microdilution (BMD) assay as per EUCAST guidelines. The heteroresistant isolates and their corresponding less susceptible subpopulations were serially passaged in media with sub-inhibitory concentrations of cefiderocol as well as in cefiderocol-free medium. The changes in frequency and/or susceptibility in the heteroresistant subpopulation were detected using mPAP. Results Eleven heteroresistant (7.53%) and twenty-two resistant (15.06%) isolates were identified. Cefiderocol susceptibility of the heteroresistant isolates after five passages in cefiderocol-free medium partially reverted to that of the parent population. However, this phenomenon was not observed in the cohort that was first passaged in cefiderocol-containing medium before passages in cefiderocol-free medium. When heteroresistant populations were passaged in cefiderocol-containing media at 0.25× MIC values, no MIC changes were observed after five serial passages; however, the proportion of less susceptible subpopulations increased by 1.2 log10 in one out of five isolates. Nevertheless, when the antibiotic pressure was removed by passaging in cefiderocol-free media for a further five serial passages, the MIC and/or frequency of the less susceptible colonies within the heteroresistant population further increased in 80% of the passaged isolates. In one isolate, the MIC of the heteroresistant sub-population increased by >32-fold while the frequency of the heteroresistant sub-population increased by 1.0 log10 in another. Conclusions The prevalence of heteroresistance to cefiderocol was around 7% amongst clinical isolates. The heteroresistant phenotypes were unstable unless exposed to cefiderocol. Such exposure may also increase the MIC and/or frequency of less susceptible cells within the heteroresistant population. This amplification can continue even after removal of antibiotic pressure. Developing methods for detecting heteroresistance to cefiderocol in clinical laboratories is essential. Clinicians need to take this phenomenon into account when planning treatment regimens to optimize the effectiveness of this invaluable addition to the antimicrobial armamentarium.

Monte Carlo flattening filter design to high energy intraoperative electron beam homogenization

Intraoperative radiotherapy using mobile linear accelerators is used for a wide variety of malignancies. However, when large fields are used in combination with high energies, a deterioration of the flatness dose profile is measured with respect to smaller fields and lower energies. Indeed, for the LIAC HWL of Sordina, this deterioration is observed for the 12 MeV beam combined with 10 cm (or larger) diameter applicator. Aimed to solve this problem, a flattening filter has been designed and validated evaluating the feasibility of its usage at the upper part of the applicator. The design of the filter was based on Monte Carlo simulations because of its accuracy in modeling components of clinical devices, among other purposes. The LIAC 10 cm diameter applicator was modeled and simulated independently by two different research groups using two different MC codes, reproducing the heterogeneity of the 12 MeV energy beam. Then, an iterative process of filter design was carried out. Finally, the MC designed conical filter with the optimal size and height to obtain the desired flattened beam was built in-house using a 3D printer. During the experimental validation of the applicator-filter, percentage depth dose, beam profiles, absolute and peripheral dose measurements were performed to demonstrate the effectiveness of the filter addition in the applicator. These measurements conclude that the beam has been flattened, from 5.9% with the standard configuration to 1.6% for the configuration with the filter, without significant increase of the peripheral dose. Consequently, the new filter-applicator LIAC configuration can be used also in a conventional surgery room. A reduction of 16% of the output dose and a reduction of 1.1 mm in the D50 of the percentage depth dose was measured with respect to the original configuration. This work is a proof-of-concept that demonstrates that it is possible to add a filter able to flatten the beam delivered by the Sordina LIAC HWL. Future studies will focus on more refined technical solutions fully compatible with the integrity of the applicator, including its sterilization, to be safely introduced in the clinical practice.

Experimental investigation of additives effect on olive pomaces pyrolysis: Oyster shells and olive mill waste water

The effects of adding solid additive Oyster Shells (OS) and liquid additive Olive Mill Waste Water (OMWW) on product yields and properties were investigated and presented during the slow pyrolysis of Olive Pomace (OP) in a lab-scale batch reactor. OP impregnation with OMWW has improved the bio-oil production, with a maximum yield of 36.3 wt %. The maximum bio-char yield, however, was obtained with the OS addition (10 wt%) and was 44.1 wt%. The Micro-GC technique was used to determine the composition of the pyrolytic gases. Following the Micro-GC results, CO2, CO, CH4 and H2 are the main components present in pyrolytic gas mixture. The highest yields of energetic vectors CH4 (22.7%) and H2 (18.7%) were recorded in the absence of any additives. In terms of the environment, adding 10 wt% of OS was beneficial as it cuts down the emission of greenhouse gases (CO2 and CO) to over 50% through absorption and shift water reactions. The Gas Chromatography/Mass Spectrometry GC/MS results showed that the pyrolytic oils were composed of phenolic compounds (33.07–58.23 PA%), acids (2.92–39.31 PA%), alcohols (3.03–10.04 PA%), aldehydes (2.81–8.29 PA%), ketones (0.97–11.46 PA%), esters (6.06–14.83 PA%). The OP impregnation with OMWW improves pyrolytic liquid quality by minimizing its corrosiveness and its instability. In fact, the lowest acids (2.9 PA %) and aldehyde (2.8 PA %) contents were obtained by OP impregnation. On the other hand, OS addition leads to an increase in the high value-added products, such as guaiacol (from 10.96 to 14.3 PA %) and syringol (from 10.48 to 13.6 PA %). Both OS addition and OP impregnation were proven to improve the bio-char quality by increasing its carbon content respectively by 14.9% and 18.4% and decreasing its oxygen content by 14.5 and 17.5%, respectively. Therefore, higher calorific values were recorded 22.6 and 23.7 MJ/kg, respectively. These calorific values suggest the suitable use of bio-chars as solid fuels.